Random sim moves into house I built

I did not know any sim could just move into a house I built. I build a house for the married couple a few days before a wedding. When I came to go live there another sim was living there. Move in with or evect well I kicked him out poor thing. Any way I might start a challenge with that sim that been put back in the gallery. I soppose some other sim might move into David's house I hope it's a ghost I known them to move in.

by the way I earned a gold for the wedding even though they decided to marry by the drinks bar than the arch oh well what ever they fancied